Franz girein



|NvENTm R- CAISSON.

F. GIREIN.

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(No Models) lINTED STATES PATENT OFFICE.

FRANZ eIREIN, oE NEW YORK, N. Y.

CAISSON.

SPECIFICATION forming part of Letters Patent No. 409,190, dated August 20, 1889.

Application filed April 27, 1889. Serial No. 308,772. (No model.)

To @ZZ whom it may concern:

Be it known that I, FRANZ GIREIN, a citizen of Great Britian, residing at New York, county and State of New York, haveinvented an Improved Caisson, of which the following is a specification.

This invention relates to a caisson so constructed that after being sunk to its greatest depth piles may be driven bodily through it, so as to give to it either a cheaper or a deeper foundation.

The invention consists in the various features of improvement more fully pointed out in the claims.

In the accompanying drawings, Figure lis atop view of my improved caisson. Fig. 2 is a longitudinal section on line Qc, Fig. l, drawn on one-half the scale.

The letter a represents the working-chamber of my improved caisson, being open at the bottom, as usual, and provided with the top or ceiling a that constitutes the floor for the superstructure. Upon the floor a there is built a stone wall h, of rectangular form, as shown. This wall is built along the edge et the iioor,is of suit-able thickness, and ineloses an open central chamber, which may, however, be traversed by the partition-wall b. The height ot' wallsl) b should, of course, be gradually increased as the caisson is sunk, so that the walls reach ultimately above the water-level.

It will be seen that the main portion of the floor a is not covered up by the superstructure, as is usually the case, but that it remains exposed within wall b. Through the y Hoor a', I make, preferably, two man-holes c c, which are provided with the necessary tools. The man-holes also serve for gaining access to the working-chamber and for the removal of the soil, (te.

Besides the manholes c, I form a large quantity of smaller perforations (Z through the lioor a within the chamber inclosed by wall l). Each of these pertorations must be temporarily closed air-tight by a suitable plug. Vhile the caisson is being sunk these perforations are kept tightly closed, so that the air from the working-chamber cannot escape through them; but after the caisson has been sunk to its maximum depth piles e are driven through the perforations CZ. These piles on being driven knock the plugs out of their seats.

It will be seen that my improved caisson is resting on or anchored by a solid pile foundatiomwhich is putin place after the caisson has been completely sunk. Moreover, every foot through which the piles are driven representsa gain in the depth of the foundation, and therefore a cheaper solid structure is obtained and a deeper and safer foundation is laid.

After the piles have been driven the work.

ing-chamber is lled up with concrete, and the space Within wall l) may also be lilled up by a suitable material.

Vhat I claim is l. The combination of a working-chamber a, having ceiling a', with a superstructure I), that partially exposes the ceiling a', and with the perforations cl made within the ceiling for the reception of piles, substantially as 

